1. Will breast cancer treatment affect what I eat?

Many people wonder what foods they should eat and avoid while having breast cancer treatment, and how their diet may change.

Breast cancer treatments such as chemotherapy and hormone therapy can have a range of side effects, some of which may affect what you want to eat and drink. Your usual routine may be disrupted, which can affect your eating pattern. You may also find that going through a stressful and anxious time affects your appetite, causing you to eat more or less than normal.

Risk of infection

Chemotherapy can cause a drop in white blood cells, which can increase the risk of getting an infection. You’ll have regular blood tests throughout your treatment to check your blood count. If you’re at an increased risk of infection, you may be advised to follow a specific diet. Your chemotherapy team will explain more about this if necessary.

We should all follow food hygiene guidelines when storing, preparing and cooking food. This is particularly important if you’re at increased risk of infection. You can find tips on storing food, and preparing and cooking food safely on the NHS website.

Healthy eating during chemotherapy if your appetite is small

If your appetite is small, or taste changes are affecting your diet, eating little and often can be better than facing a large meal. It may help to:

Eat five to six small meals or snacks each day instead of three bigger meals

Nausea and vomiting

Nausea (feeling sick) and vomiting (being sick) can be a problem for some people during and after their chemotherapy treatments. Anti-sickness drugs can help with nausea and vomiting. Your chemotherapy team can help you find one that works for you.

Drink plenty of fluids, such as water or herbal teas. Taking frequent sips is better than trying to drink large amounts in one go.

Eating little and often can help if you’re feeling sick. Herbal teas such as mint or ginger can also help settle the stomach.

Some people find that eating cold food makes them feel less sick because hot food can produce more of a smell.

Sore mouth

Chemotherapy can make your mouth sore or dry, making it uncomfortable to eat.

You might find it helpful to:

Clean your teeth or dentures with a soft brush after eating and floss gently

Use an alcohol-free mouthwash (your chemotherapy team may recommend one)

Choose soft or liquid foods such as soups, stews, smoothies and desserts

Soothe your mouth and gums with ice cubes and sugar-free ice lollies

Drink sugar-free fizzy drinks to freshen your mouth

Use a straw to drink

Avoid crunchy, salty, very spicy, acidic or hot foods

Avoid citrus drinks like lemon, lime, orange and grapefruit juice

If you have dentures, clean them regularly and try not to wear them all the time.

Smoking and drinking alcohol can make a sore mouth worse.

Taste changes

Your taste may change during chemotherapy, making foods taste bland or different. You may prefer to eat strongly flavoured foods, and using herbs and spices in cooking may help. Try a variety of foods to find the ones you like the best. As well as going off your usual foods, you may find that you like foods that you previously did not like.

Some types of chemotherapy can give you a metal taste in your mouth. Using reusable plastic or wooden cutlery, instead of metal, can help reduce the metal taste. Using glass pots and pans to cook with can also help.

Constipation

Eating and drinking less than usual, being less active and taking certain medications can all lead to constipation.

Eating high-fibre foods can help if you’re constipated. These include:

5. Will hormone therapy affect my diet?

Weight gain

High cholesterol

Hormone therapy drugs such as anastrozole and letrozole can increase the level of bad cholesterol in the blood.

If you have too much bad cholesterol it can build up in the artery walls, leading to artery disease or other health conditions.

Following a healthy diet and maintaining a healthy body weight can help to reduce your levels of bad cholesterol. Your doctor can tell you more about how cholesterol levels are measured and what dietary changes you may need to make.

6. Shopping and cooking during treatment

Simple tasks like shopping and cooking can seem exhausting during your treatment and as you recover. Try to accept any offers of help, even if you’re used to coping on your own. You can also take advantage of online shopping or ask local shops if they have a telephone ordering and delivery service.

It’s important to have fresh food in your diet, but if you can't shop regularly, frozen and tinned fruit and vegetables are full of nutrients and can be eaten every day. Choose tinned fruit in juice rather than syrup and tinned vegetables that have less salt.

7. Diets for other medical conditions

If you’re already following a specific diet because you have a medical condition – such as diabetes, Crohn’s disease or irritable bowel syndrome (IBS) – having breast cancer doesn’t mean your diet has to change.

However, if you’re concerned about how your breast cancer treatment may affect your diet or any existing condition, talk to your breast care nurse or treatment team. They can talk to a dietitian or other medical staff to ensure any existing condition remains under control during your treatment.

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